Metrology, the science of measurement and its application, plays a critical role in the accuracy of GIA’s research and laboratory services. The metrology team closely monitors the performance of ...

Figure 1. This gold ring with a phoenix motif features a Neyshabur turquoise (13 × 17 mm), with a 0.02 ct ruby on each side and diamond accents. Courtesy of Taktala Jewelry, Tehran. Turquoise is an ...

Figure 1. This 0.33 ct Fancy blue diamond was confirmed to be a composite of CVD synthetic type IIb diamond overgrowth on a natural type Ia substrate. Photo by Sood Oil (Judy) Chia. Nitrogen is the ...

Saltwater bead cultured pearls dominating the global pearl market are produced by mollusk species in the Pinctada genus, including P. maxima (South Sea), P. margaritifera (Tahitian), and P. fucata ...

The micro-world of gems lies at the very core of gemology. Information gathered from observations through the microscope serves as the very foundation for many conclusions drawn on a specimen, ...

Jadeite jade is one of the most important aggregate gems in today’s global marketplace, with known sources in Myanmar, Japan, Russia, and Guatemala. Among them, Myanmar is the most legendary and still ...

The specimen was obtained from Luciana Barbosa of Barbosa Minerals (Asheville, North Carolina). It came from a recent discovery at the Milpo mine in the Atacocha mining district of Pasco Province, ...

GIA is adding a report comment for the historical trade term 'Hanadama' to distinguish a designated quality range of cultured Akoya pearls. Image courtesy of GIA. Protecting consumers and meeting ...

Carved single-crystal diamond rings are rare, with few examples to reference (see Spring 2020 Lab Notes, pp. 132–133). But with advancing technology in the laboratory-grown diamond industry, the ...

Figure 1. This 0.57 ct taaffeite from Sri Lanka measures 5.63 × 4.00 × 3.21 mm. Photo by Elise A. Skalwold. The lovely chromium-bearing purplish red taaffeite from Sri Lanka seen in figure 1 is home ...

A rare star sapphire of Kashmir origin, mounted in a combination ring and pendant (figure 1), was recently examined in the New York laboratory. Kashmir has long been regarded as the most sought-after ...

業界で最も権威のある資格のひとつであるGIAのグラジュエイトジェモロジスト (GG) ® プログラムでは、宝飾品業界で成功 ...